Metal wood golf club heads have become increasingly popular over the past twenty to thirty years with the improvement of metal casting techniques. It has been discovered that metal woods provide an increase in the accuracy and length of a given golf shot when compared with the traditional woods made of wood.
To date most metal wood manufacturers have used a casting process, wherein the casting process has produced the head in a number of pieces and in particular, two components including a sole plate and a head shell comprising the hitting face, hosel and top or crown portion. The problem with casting is that metal casting techniques inherently produce a variety of surface imperfections, which must be removed prior to sale, but require considerable time and effort to do so. Another problem with casting is that the wood design and in particular the relationship between the hosel and the hitting face and sole arrangement cannot be easily and economically varied when a casting process is used since a change in the die is required for each variation.
Some attempts have been made to address the problems of casting by stamping the club head components from sheet metal. One example of this process is described in U.S. Pat. No. 5,232,224 in the name of Zeider. This patent discloses a method of forming a metal wood club head from four separate components, wherein the components including the head base, face plate and crown plate, have been stamped out of metal sheet, and also including a hosel tube. The components are welded together, wherein the head base can be machined to allow the face plate to be attached at different angles, resulting in clubs with different loft angles. Additionally, because the hosel is a separate piece the angle of fixing can also be varied. The problem with manufacturing golf club heads in this manner is that the components are extremely difficult, time consuming and thus costly to align and require special jigs to accurately align the components relative to each other and in particular correctly align the hosel relative to the other components.
Furthermore if the hosel, and thus the centre line of the shaft that fits into the hosel, is not perfectly aligned with the hitting face and sole of the club, the player will not be able to accurately align the hitting face with the ball, resulting in a larger than usual number of wayward shots.
Thus, it is the object of the present invention to provide a method of manufacturing of a metal wood golf club head which addresses some of the problems of the prior art. It is also an object of the present invention to provide a metal wood golf club head made by the improved method.